Seascape

This page presents briefly the notion of seascape. The "seascape" term is borrowed from the landscape ecology terminology that aims to quantify the ecological and biogeochemical interactions between different ecosystems through their boundaries (or ecotones). Anthropogenic influence is also a key component of the landscape approach. Coral reefs are tightly connected to land, wetlands, bays, gulfs and oceanic and atmospheric systems. They may also be under the influence of human populations settling in coastal areas or influencing the equilibrium of watersheds far upstream.

Each Landsat image covers roughly a square of 180x180 km, which is adequate to put coral reefs in their "seascape" context. Reef systems typically cover few tens of square kilometers in each image, but their position between other ecosystems can be quantified using various landscape ecology indicators that still need to be defined for most reef systems. For example, the South Florida seascape (Upper and Middle Florida Keys #1) shows coral reef areas along the shelf open to the Gulf Stream current, but also under the influence of the water discharge from the Everglades and Florida Bay, and under the influence of increasing human populations living in the Florida Keys. The South-west Cuba seascape (#2) presents a configuration very similar to the Florida Keys. Coral reef areas lie along the outer edge of the Canerreos Archipelago, bordered by the shallow Gulf of Batabano, the deep Gulf of Calzone and the Bay of Pigs. These reefs are under the influence of the water discharge from the Zapata Peninsula wetlands and the turbid waters of the Gulf of Batabano. Seascapes can be also studied for oceanic systems such as Pacific atolls. In this case, exchange of matter and energy occur between two ecological systems: the ocean and the lagoon. The ecotone is the rim of the atoll, which can also be considered as a specific system itself since many assemblages of habitats and benthic communities occur only there. Atolls are diverse in size, depth, aperture to the ocean, lagoon structure and rim structure and therefore provide a large range in seascape / landscape parameters as shown by the small shallow reticulated Bellinghausen Atoll (Society Archipelago, French Polynesia), the medium, closed and deep Ahunui Atoll (Tuamotu Archipelago, French Polynesia) and the large, deep, very open Bikini Atoll (Marshall) (#8).